I have been studying and repairing computers for 15 years myself,learned alot from trial and error also (The School of Hard Knocks).i am CompTIA certified and getting a Associates in Specialized Technology in PC Maintenance Technology.I do have to disagree on the RAM part.I have purchased RAM that was DOA on arrival and that was testing in more than one machine with no obvious physical damage.I have seen machines that didn't like certain brands of RAM like HP some i have worked on just wouldn't work with Kingston Value RAM and the RAM was rated for the system.Corsair I have yet to run across that problem.I have a stick of Ram now on my parts shelf that came out of a HP that i can't get to work in any HP that comes in.It is a good stick because i use it in my test machine.It is a Mega Trends stick with a HP sticker on it.
First there's this:
"I've yet to actually
see defective RAM short of obvious physical damage"
It's certainly nice to know of someone that does have some formal training in these boxes, however, as a formally trained technician in a entirely different field I can say that such is just a place to begin, the rest is by experience or "seat of the pants".
Although rare I do see equipment that is just as DOA as the RAM that you mentioned, but I tell the client that the best thing for them to do is take it back to the store if possible, best all the way around in the long run. With a lot of electronic parts, taking it back isn't an option even with the receipt, you take it out of the original packaging and it's YOURS.
In the past 5 yrs. or so there's been all sorts of RAM made for a variety of applications and machines, and some, even if they fit, don't work. When the x386 * x486 machines (and earlier) (Compaq and IBM RAM were also quite different) came out the basic difference (aside from speed and capacity) in RAM was parity and non-parity, you couldn't mix the two nor use either in a machine that wasn't designed for it.
There are, without doubt, a wide variety of mysteries that are run in to in any service arena that defy explanation.
I don't give suspected RAM problems much pause because it's never been much of an issue at the finish line. If there is one it's usually because someone stuck the wrong module in in the first place.
Ever see a glass Coke bottle with a Pepsi bottle cap?
A certain make of auto transmission, while sitting still, would go from Drive to Reverse for no explicable reason, oh yes, the engineers said it's impossible, unfortunately that meant beans to the TV cameraman that got it all on tape, and that ended up "News at 6 o'clock". Can you imagine the red faces at the designers conference table?
I had a machine that needed parts, the usual manner was used to order them, the manuf. wrote back that they didn't make any such thing. I peeled off the Mod. ID label and sent it and all the correspondence back that was received, yes, we made a mistake, and, oh btw, here's the parts you ordered.
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